The most common way to cite sources is to use a "Works Cited" or "References" list at the end of your research paper. "Works Cited" is the title of your list of citations when using the MLA (Modern Language Association) format; the title "References" is used when citing sources using APA (American Psychological Association) style. The list includes a citation for each of the sources you used to write your paper. The citations are formatted in a consistent style according to whichever citation format is used. Many instructors specify which format they prefer; some leave it up to the students as long as they maintain one consistent format.
A "Bibliography" is not the same as a "Works Cited" or "References" list. In your "Works Cited" or "References" you only list items you have actually cited in your paper. In a "Bibliography" you list all of the material you may have consulted in preparing your essay, whether or not you have actually cited the work. A "Bibliography" may include any sources related to the topic of the research paper.
The list of all citations is commonly organized in a single alphabetical list. Each different type of source--book, magazine article, journal article, newspaper article, article from a reference book, World Wide Web page--has a precise format that is specified by the given format (MLA, APA or other).